An oral French maritime pine bark extract improves hair density in menopausal women: A randomized, placebo‐controlled, double blind intervention study

Abstract Background and Aims Female pattern hair loss affects females of all ages with a trend to increase after menopause. This disorder may have significant psychological impact and lead to anxiety and depression. Objective In a single center, double blind, randomized, placebo‐controlled study, the effects of oral Pycnogenol® intake (3 × 50 mg/day for a total of 6 months) on hair density, scalp microcirculation, and a variety of skin physiological parameters was studied in Han Chinese menopausal women (N = 76) in Shanghai, China. Methods Measurements were taken at the beginning and after 2 and 6 months, respectively. Hair density was determined by digital photographs and further evaluated by Trichoscan software. Transepidermal water loss was measured by a humidity sensor in a closed chamber on the skin surface. Changes in microcirculation were detected as resting flux on the scalp by reflection photoplethysmography. Results Pycnogenol® intake significantly increased hair density by 30% and 23% after 2 and 6 months of treatment, respectively, as detected by Trichoscan® evaluation of digital photographs. Interestingly, photoplethysmography revealed that this beneficial effect was associated with a decrease in resting flux of the scalp skin, which might indicate an improvement of microcirculation. None of these effects were observed in the placebo taking group. In addition, a significant transient decrease of transepidermal water loss was observed in scalp skin under Pycnogenol,® but not placebo treatment. Conclusion Oral intake of Pycnogenol® might have the potential to reduce hair loss in postmenopausal women.


| INTRODUCTION
Female pattern hair loss (FPHL) is a general diffuse hair thinning over the central scalp varying among population groups which ordinarily increases with age. 1 Although no robust epidemiological data are available, due to a lack of unifying criteria, FPHL is very likely to be a frequent disorder. Accordingly, Gan and Sinclair 2 studied the prevalence of balding among Caucasian women in Maryborough, Victoria, Australia. Based on a five level staging with level one being the normal status these authors found 23% of middle aged women in an age range from 40 to 49 years suffered from mild hair loss, and that this percentage increased in older ages. According to Williams et al., 3 thinning hair in women is commonly associated with the menopause. Hormonal changes in menopause affect growth rate, percentage anagen, hair diameter, and diameter distribution, while scalp hair density decreases with age leading to heightened perception of decreased scalp coverage. 4 In addition, age-related changes in dermal sheath and dermal fibroblasts might contribute to the observed impact on hair growth. 5 In the United States, approximately 21 million women are affected. 6 Recently, the prevalence of FPHL in Asian women was reviewed. Starace et al. found a similar prevalence, again with an age-related trend, which, however, seems to be lower than in Caucasians. 1,[7][8][9] Although FPHL is no disease, it is regarded as a disorder with a significant psychological impact, which may lead to anxiety and depression. 10,11 Human hair is synthesized in the hair follicle through a growth cycle including a long phase of active fiber production (anagen) and a shorter resting phase (telogen), interspaced by short lasting phases or regression and neomorphogenesis. 12 On the scalp, hair remains in the anagen phase for a period of 2-to 6-years, whereas that of telogen is approximately 100 days. 13 Approximately 15%−20% of scalp hairs are usually in the telogen phase. 14 FPHL is characterized by a follicular regression, which in some cases is associated with elevated androgen levels or microinflammation. 15 An involvement of vascularization is suggested by observations indicating a decreased subcutaneous blood flow. Also, immunohistopathological studies comparing VEGF localization in alopecia skin versus normal skin indicate decreased angiogenesis. 16,17 Along the same lines, Minoxidil, a potassium channel opener, which has been FDA approved for the treatment of alopecia, is supposed to enhance angiogenesis around the hair follicle. 18 Pycnogenol ® is a proprietary bark extract from the French maritime pine tree. It mainly contains 70 ± 5% procyanidins built from condensed monomers of catechin and epicatechin. Based on a recent update by the American Botanical Council of the Scientific and Clinical Monograph for Pycnogenol ® it is stated that an independent panel of toxicology experts has classified PYC as generally recognized as safe (GRAS) based on clinical safety and preclinical toxicology data. 19,20 Oral intake of Pycnogenol ® is best known for its antioxidative and antiinflammatory effects. 16 In addition, Pycnogenol ® intake also improves microcirculation as was shown in patients suffering from venous insufficiency such as diabetic ulcers and diabetic microangiopathy. Accordingly, Pycnogenol ® intake decreased the skin flux at rest, and this decrease was associated with an increase in pO 2 and a decrease in pCO 2 . 17,21 This effect is not specific for this patient group, because even in healthy young subjects, intake of Pycnogenol ® was accompanied by a decrease in the resting flux. 22 Positive effects of Pycnogenol ® intake on endothelial function were also observed in patients with stable coronary artery disease in a double blind, randomized placebo controlled cross over study, showing a significant increase in flow mediated dilation after 8 weeks. 23 In the present randomized, double-blind, placebo-controlled study we asked if oral administration of 3 × 50 mg Pycnogenol ® a day over a 6-month period will affect (i) total hair density and (ii) scalp microcirculation in postmenopausal Chinese women. actively cooperated to participate in the study, agreed to follow the instructions of the investigator and to visit the study center at the agreed times; they had also agreed not to use any additional nutritional supplements during the study, to retain the same hair style, hair color, and hair regimen throughout the study. All study subjects signed an informed consent form after the nature and the purpose of the study had been explained to them. Baseline characteristics of participants are given in Table 1 T A B L E 1 Baseline characteristics of the participants per (protocol)

| Study materials
The test products were Pycnogenol ® and placebo capsules; the latter looked identical to Pycnogenol, ® but did not contain any active substances and only consisted of cellulose. Both were provided by Horphag Research. All test products were stored at room temperature in a secure area before study start. All supplements were supplied in identically packed, coded containers. For the intervention, test products were orally administered in a dose of 1 pill three times a day with the meals for a total of 6 months. The Pycnogenol ® dose was 150 mg (3 × 50 mg) per day.

| Study design
At baseline, hair status and treatment responses were documented by taking digital photographs, which were further evaluated by Details for both groups of the randomized, placebo-controlled, double blinded study testing the efficacy of the oral supplement Pycnogenol ® versus a placebo. At visit 0 (V0) demographic data were obtained, and a medical examination was done. At V1, informed consent was obtained, test area was marked, digital photograph was taken, microcirculation was measured, hair was colored in the test area. At V2, digital photographs were taken, subjects were allocated to either of the two groups A/placebo or B/Pycnogenol, ® received medication and were assessed for skin physiological parameters as indicated.
the actual study design is based on previous studies, where similar doses and treatment modalities resulted in significant effects on study outcomes during a time frame of 2 to 3 months. 23,27

| Statistical analysis
Normal distribution of the data was tested using the Shapiro−Wilk test.

| RESULTS
In this randomized, placebo-controlled, double blind intervention study, we assessed the effect of a nutritional supplement consisting of 70 ± 5% procyanidins built from condensed monomers of catechin and epicatechin in a dose 3 × 50 mg Pycnogenol ® a day over a period of 6 months on hair loss in Chinese menopausal women. From the 76 women initially enrolled in the study, 13 subjects withdrew from the study before distribution of medication on visit 2. Thus, the final number of subjects which completed the study was 63 with a mean age of 54 years as shown in Figure 1A. The study design is depicted in Figure 1B. The drop-out rate was similar as observed for other intervention studies employing Pycnogenol as add-on in comparison to best treatment taking 6 months or longer. [28][29][30][31] Hair density, detected by the validated Trichoscan analysis from digital photographs, was assessed in both treatment groups at the beginning and after 2 and 6 months of treatment (Figure 2A)  which means a decrease of 21% and 44% after 2 and 6 months of treatment, respectively. Of note, the effect after 6 months was significantly smaller as compared to the baseline.
The effects of Pycnogenol ® intake on scalp skin physiological parameters such as skin hydration and TEWL were also studied.
Hydration of scalp skin was not significantly affected by Pycnogenol ® or placebo intake. Given as median (25%−75% percentiles) the following results were obtained: In the placebo group, we measured a change of 1.5 (−6.50 to 11.25) after 2 months and a change of 8. Adverse events and serious adverse events were not observed during the whole study. Scalp conditions such as dandruff, greasy scalp, dry scalp, psoriasis, burning sensation, prurigo, inflamed scalp, eczema, and tautness were addressed in investigator's questionnaires at the beginning and after 6 months.
None of the listed medical conditions were either present at the beginning of the study nor did they develop during the study (Figure 4).

| DISCUSSION/CONCLUSION
We here report that daily intake of Pycnogenol ® over 2 and 6 months significantly increased hair density in postmenopausal Han Chinese women, while the intake of placebo failed to do so. The increase of hair density by trend within the placebo group might be explained by the seasonality of hair growth, showing a maximal proportion in telogen hair in July. 13 As the study started in the end of August, an increased loss of hairs might have affected the hair density at the time of study start, when it might have been lower than in other seasons.
The precise mechanism by which Pycnogenol ® intake improves hair density is currently not known. Of note, we observed that the beneficial effects of Pycnogenol ® on hair density were associated with a decrease Pycnogenol ® treatment but not after infusion of an endotheliumindependent vasodilator such as sodium nitroprusside. 34 As addition of the NO synthase inhibitor N G -monomethyl-L-arginine was able to completely inhibit the effect of Pycnogenol ® on forearm blood flow in response to acetylcholine, it was suggested that Pycnogenol ® might impact endothelium-dependent vasodilatation by increasing NO production. 34 Similarly, Pycnogenol intake significantly decreased the wheal and flare response to a local histamine injection in young females assessed as wheal area, redness and time frame until complete wheal disappearance, which was accompanied by a significant decrease in capillary permeability detected by straingauge plethysmography. 26  In the aggregate, these reports and the present study corroborate the ameliorating effect of Pycnogenol ® on microcirculation.
Given the fact that daily Pycnogenol ® intake was well tolerated, the present study extends the spectrum of potential indications for Pycnogenol ® intake to FPHL.

DATA AVAILABILITY STATEMENT
The data that support the findings of this study are available on request from the corresponding author. The data are not publicly available due to privacy or ethical restrictions.

ETHICS STATEMENT
The study was approved by the local ethical committee. All study subjects signed an informed consent form after the nature and the purpose of the study had been explained to them.

TRANSPARENCY STATEMENT
The lead author Jean Krutmann affirms that this manuscript is an honest, accurate, and transparent account of the study being reported; that no important aspects of the study have been omitted; and that any discrepancies from the study as planned (and, if relevant, registered) have been explained.